In control panels for electrical equipment, space is an important consideration for the positioning and spacing of the various devices and the routing of wires through the control panel.
Conventional fuse holders for multiple fuse arrangements typically mount the fuses adjacent to one another and parallel to the back panel of the control panel, which takes up considerable space. In addition, the fuses and the connecting terminals are exposed, which can present a danger to an operator working in the panel.
The present invention, generally, provides a fuse holder for three or more fuses that solves the problems of space and safety in the art.
More particularly, the present invention provides an overcurrent protection module having a fuse holder for three or more fuses, for example, for a three-phase circuit, that takes up less room in a control panel than does a conventional fuse holder. The overcurrent protection module of the present invention is narrower than conventional fuse holders carrying the same number of fuses.
The overcurrent protection module according to the present invention provides a unit that contains three or more fuses in an enclosed unit to protect an operator from contact with exposed electrical terminals or other live elements. The overcurrent protection module according to the present invention also provides a fuse holder in a base unit that is removable from the base unit to allow replacement of fuses in the fuse holder without exposing an operator to danger of electrical contact.
According to another aspect of the present invention, the overcurrent protection module includes a base unit that mounts on a panel or a DIN rail so that a containing space in the base unit is positioned perpendicular to the plane of the panel or DIN rail, and in line with conventional wiring orientation. The overcurrent protection module also includes a fuse holder that inserts in the base unit. The fuse holder is formed to hold three or more fuses in a single plane that, in an inserted position of the fuse holder, is also perpendicular to the plane of the panel or DIN rail.
According to a further aspect of the invention, the fuse holder includes individual slots for securing a fuse and means connecting each fuse in an electric circuit in the base unit. The electrical connection means includes plug-type connectors at the opposite end portions of the fuse slots. The plug-type connectors are positioned to connect with mating connectors in the base unit when the fuse holder is inserted in the base unit. According to the invention, the plug-type connectors are arranged parallel to the plane of the fuse slots.
According to another aspect of the invention, load and line terminals are provided on opposite side walls of the base unit. All of the line terminals are located on a first side wall of the base unit and all of the load terminals are located on a second side wall, opposite to the first side wall. This arrangement simplifies electrically connecting the overcurrent protection module in the control panel and simplifies the routing of the connecting wires, which contributes both to safety and saving space on the control panel.
According to yet another aspect of the invention, the electrical connection means to connect the fuses to the line and load terminals include electrical conductors connecting the plug-type connectors to the load and line terminals. The conductors for the load terminals are arranged in a single plane that is perpendicular to the plane of the plug-type connectors and parallel to the bottom portion of the base unit. Similarly, the conductors for the line terminals are also arranged in a single plane perpendicular to the plane of the plug-type connectors. The arrangement of the load and line conductors advantageously allows the at least three fuses to be arranged in a narrow space with the load and line terminals at opposite sides of the base unit.
According to another aspect of the invention, the base unit electrical connection means comprises a first terminal block mounted in the base unit adjacent to the load terminals and a second terminal block mounted adjacent to the line terminals, both terminal blocks oriented parallel to the bottom of the base unit. Three individual connectors are supported by the first terminal block and positioned in a plane extending upwardly from the terminal block and perpendicular to the second side wall of the base unit. Each of the connectors is attached to an electrical conductor supported in the first terminal block. Each conductor is also connected to one of the load terminals. Three individual connectors are supported by the second terminal block and positioned in a row perpendicular to the first wall. Each of the connectors is attached to an electrical conductor disposed in the second terminal block, and each conductor is connected to one of the line terminals.
According to a preferred embodiment of the invention, a portion of the second terminal block extends through the first side wall and supports the line terminals and a portion of the first terminal block extends through the second side wall and supports the load terminals.
According to a preferred embodiment of the invention the base unit electrical connectors and the fuse holder electrical connection means include mating plug-type connectors for ease of connecting and disconnecting the fuse holder by movement of the fuse holder respectively into and out of the base unit.